The Internet includes a large number of computer networks connected to each other such that messages contained in internet protocol (IP) packets are transferred from a source computer to a destination computer through any number of different computer networks. Each of these computer networks may be operated by different internet service providers (ISPs).
A large volume of traffic traversing any given network may have sources or destinations outside of the network. For example, a network hosting a popular web site may receive a large number of web site hits from computer systems hosted within a competing network. The competing network may expend a large amount of bandwidth servicing the web site that it does not host. Additional bandwidth may be expended by a network servicing file transfers or email to and from private networks, file systems, or computer systems hosted on a different network.